Blast furnace plug

ABSTRACT

An apparatus for centering a tap drill is provided herein. The device includes a body made of a refractory material that has a tapered shape and a connector secured to body configured to permit connection of the body to a tap drill bit. In addition, a method of operating a blast furnace is provided herein. The method includes providing a blast furnace plug having a refractory body having a tapered configuration. Securing the blast furnace plug to a tap drill bit. Aligning the blast furnace plug with a tap hole plugged with mud, and inserting the blast furnace plug into the mud to create an indentation in the mud having a tapered configuration. Removing the blast furnace plug from the tap drill bit, aligning the tap drill bit with the indentation and tapping the blast furnace.

This invention relates generally to blast furnace iron making operationsand more particularly to a plug for use on a tap drill.

BACKGROUND

Raw materials, including iron ore, limestone, and coke are added to ablast furnace 140 where they are heated (FIG. 1). As the raw materialsare heated, molten iron 160 forms at the bottom of the blast furnace 140and a layer of slag 150 forms on top of the molten iron 160. After asufficient volume of molten iron 160 builds up at the bottom of theblast furnace 140, the blast furnace 140 is tapped to remove the molteniron 160. A tap drill 110 having a drill bit 115 is used to tap theblast furnace 140 by drilling out the tap hole 130. As the tap drill 110and drill bit 115 is removed, molten iron 160 flows through the tap hole130 into a trough 120 where it is routed to a waiting rail car (notshown).

When all of the molten iron 160 is drained out of the blast furnace 140,or after a desired amount of iron 160 has been drained from the blastfurnace 140, the tap hole 130 is sealed (FIG. 2). The tap hole 130 issealed with a mud gun 210. An anhydrous mixture, commonly referred to as“mud” or “clay” is loaded into the mud gun 210. The mud gun 210 rotatesfrom a non-operating or resting position to its operating position (asshown). In its operating position the mud gun 210 is positioned so thatthe nozzle 215 of the mud gun 210 is aligned with the tap hole 130. Mud170 is extruded through the nozzle 110 and forced into the tap hole 130.The mud 170 forces the residual molten iron 160 and slag 150 that is inthe tap hole 130 back inside the furnace 140. Inevitably, however, notall of the iron 160 and slag 150 is pushed back into the furnace 140i.e., some of the iron 160 or slag 150 remains in the tap hole 130 andmixes with the mud 170 forming a mud and ore residue 180. The mud gunnozzle 110 remains in place until the mud 170 begins to dry or cure, andis rotated back away from the blast furnace 140.

Occasionally, the blast furnace 140 experiences a break out. A break outoccurs when the tap hole 130 is not sealed properly and the iron 160unexpectedly breaks through the mud 170 and stars flowing out of theblast furnace 140. An unexpected breakout is dangerous and may result ininjury, damage, and loss of productivity. In addition, if the breakoutis not rapidly contained, significant clean up labor is required. In thepast, a wooden plug has been hammered onto the drill bit 170 and anoperator attempts to swing the wooden plug into the tap hole to stop orstem the flow of iron 160 into trough 120 until the mud gun 110 isloaded with mud 170 and ready to swing into place.

When a sufficient volume of molten iron 160 builds up in the blastfurnace 140 the process may be repeated. Ideally, the tap drill 110 anddrill bit 115 are rotated into place and drill a clean hole through thecenter of the tap hole 130. Often the tap drill bit 170 walks or movesaround before it penetrates very far into the tap hole 130 resulting inan irregular shaped, or oversized hole. This is undesirable because thesize of the drilled hole controls the speed of the flow of molten iron160 out of the blast furnace 140.

SUMMARY

An apparatus for centering a tap drill is provided herein. The deviceincludes a body made of a refractory material that has a tapered shapeand a connector secured to body configured to permit connection of thebody to a tap drill bit. In addition, a method of operating a blastfurnace is provided herein. The method includes providing a blastfurnace plug having a refractory body having a tapered configuration.Securing the blast furnace plug to a tap drill bit. Aligning the blastfurnace plug with a tap hole plugged with mud, and inserting the blastfurnace plug into the mud to create an indentation in the mud having atapered configuration. Removing the blast furnace plug from the tapdrill bit, aligning the tap drill bit with the indentation and tappingthe blast furnace.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 (Prior Art) is a cross-section of a blast furnace, a tap hole, atap drill and a trough;

FIG. 2 (Prior Art) is a cross-section of a blast furnace, a tap hole, amud gun nozzle and a trough;

FIG. 3 is an embodiment of a blast furnace plug;

FIG. 4 is a cross sectional view of a blast a furnace, blast furnaceplug attached to a tap drill used in accordance with one embodiment, atap hole and a trough; and

FIG. 5 is also a cross sectional view of a blast furnace, and blastfurnace plug attached to a tap drill used in accordance with anotherembodiment, a tap hole and a trough.

DETAILED DESCRIPTION

FIG. 3 illustrates an embodiment of a blast furnace plug 300. In oneembodiment, the blast furnace plug 300 has a conical body 310, which ispreferably made of a refractory material, and more preferably, a 3100°to 3400° refractory material. Blast furnace plug 300 may also includerebar 320 to increase the strength and durability of the blast furnaceplug 300. Blast furnace plug 300 includes a connector or drill head 330.Drill head 330 is sized to fit over drill bit 115, so that blast furnaceplug 300 may be secured to tap drill 110 without having to remove drillbit 115 (FIG. 1).

Blast furnace plug 300 has tapered body, more specifically, the body ofthe illustrated embodiment has a frusto-conical shape. Other shapes,such as conical, or conical with a rounded end are contemplated andwithin the scope of the present invention.

Blast furnace plug 300 has two primary functions. The first function isto ensure that the tap drill 110 and drill bit 115 are centered in thetap hole 130 when the blast furnace 140 is tapped. FIG. 4 illustratesone method of ensuring that tap drill bit 115 is centered when drillinga tap hole. Blast furnace plug 300 to the end of tap drill bit 115 bysliding drill head 330 over the drill bit 115. When the mud gun 210 ismoved away from tap hole 130, tap drill 110, drill bit 125 and blastfurnace plug 300 may be swung over trough 120 and lined up with thecenter of tap hole 130. Blast furnace plug 300 may be forced into taphole 130 creating an indented portion at the center of tap hole 130.This operation may be completed at any time, however, it is preferableto conduct this operation immediately after removing the mud gun nozzle215 from the tap hole 130. The indentation (not shown) caused by blastfurnace plug 300 is round and tapers toward the center of tap hole 130.

The indentation preserves the integrity of the tap hole. During thetapping operation, blast furnace plug 300 is removed from the end ofdrill bit 115 and the tap drill 110 is moved into position. Drill bit115 is inserted into the indentation caused by blast furnace plug 300.The indentation causes the drill bit 115 to be centered on the tap andprevents the drill bit 115 from walking during the tapping operation.Accordingly, the resulting drilled tap hole has uniform opening and auniform bore, which serves maintain the integrity of the tap hole 130and aids in controlling the speed and flow of the iron 160 is morecontrolled.

In addition, the blast furnace plug 300 may be used as a safety plug asillustrated in FIG. 5. During normal operation, blast furnace plug 300is connected to tap drill bit 115 after the taping operation or whilethe tap hole is being plugged with the mud gun 210 so that the blastfurnace plug 300 may be used to create the centering indentation afterthe mud gun 210 operation is complete. The blast furnace plug 300 ispreferably left attached to the tap drill 210. In the event of anunexpected break out 500, the tap drill 210 with the blast furnace plug300 attached thereto may immediately be swung into position and theblast furnace plug 300 forced into the tap hole 130 to plug the tap hole130 until the break out 500 is stopped or the mud gun 210 is refilledand ready to re-plug the tap hole 130.

While the present invention has been illustrated by the description ofembodiments thereof, and while the embodiments have been described inconsiderable detail, it is not the intention of the applicants torestrict or in any way limit the scope of the appended claims to suchdetail. Additional advantages and modifications will readily appear tothose skilled in the art. For example the shape of the blast furnaceplug 300 may have a rounded end, or a pointed end. Therefore, theinvention, in its broader aspects, is not limited to the specificdetails, the representative apparatus, and illustrative examples shownand described. Accordingly, departures may be made from such detailswithout departing from the spirit or scope of the applicant's generalinventive concept.

1. A device for centering a tap drill comprising: a body made of arefractory material; the body having a tapered configuration; and aconnector secured to body configured to permit the connection of thebody to a tap drill bit.
 2. The device of claim 1 wherein the taperedbody has a conical shape.
 3. The device of claim 2 wherein the taperedbody has a frusto-conical shape.
 4. The device of claim 2 furthercomprising one or more pieces of reinforcement material located withinthe conical body.
 5. The device of claim 2 wherein the refractorymaterial is a 3100° to 3400° refractory material.
 6. The device of claim2 wherein the refractory tapered body has a rounded end.
 7. The deviceof claim 2 wherein the refractory tapered body has a pointed end.
 8. Anapparatus for a blast furnace comprising: a tapered body comprising arefractory material; at least one reinforcing member within the taperedbody; and a drill head secured to the tapered body for connecting thetapered body to a tap drill bit.
 9. The device of claim 8 wherein thetapered body has a conical shape.
 10. The device of claim 9 wherein thetapered body has a frusto-conical shape.
 11. The device of claim 8wherein the refractory material is a 3100° to 3400° refractory material.12. A method of operating a blast furnace comprising: providing a blastfurnace plug having a refractory body having a tapered configuration;securing the blast furnace plug to a tap drill bit; aligning the blastfurnace plug with a tap hole plugged with mud; inserting the blastfurnace plug into the mud; creating an indentation in the mud having atapered configuration; removing the blast furnace plug from the tapdrill bit; aligning the tap drill bit with the indentation; and tappingthe blast furnace.
 13. The method of operating a blast furnace of claim12 wherein the tapered configuration is a frusto-conical configuration.14. The method of operating a blast furnace of claim 12 whereinrefractory material is a 3100° to 3400° refractory material.
 15. Themethod of operating a blast furnace of claim 12 wherein the taperedconfiguration includes a rounded end.
 16. The method of operating ablast furnace of claim 12 wherein the tapered configuration includes apointed end.
 17. A method of stopping a breakout of molten iron from ablast furnace: providing a blast furnace plug comprising a tapered bodymade of refractory material and a connector secured to the body forconnecting the blast furnace plug to the end of a tap drill bit;securing the blast furnace plug to a tap drill bit; aligning the blastfurnace plug with a tap hole during a breakout; and inserting the blastfurnace plug into the tap hole until the molten iron stops flowing outof the tap hole.